Press guard



F. A. FULLER PRESS GUARD F b, 10. 7192s. 1,525.64;

Filed Aug. 25. 1923 Sheets-Sheet 1 INVENTOR ATTORNEY Feb. 10. 1925.

F. A. FULLER PRESS GUARD Filed Aug. 25. 1923 2 Sheets-Sheet 2 N Q 9 Q umIii; Iv

ATTORNEY I YENTQR lichdfw BY together with others, such as conveniencein.

Patented Feb. 10, i925.

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FRANZ A, FULLER, 0F NEWARK, NEW JERSEY.

ERESS GUARD.

Application filed August 25, 1923. Serial No. 659,281.

To all whom it may concern:

Be it known that I, FRANZ A. FULLER, a citizen of the United States,residing at Newark, in the county of Essex and State of New Jersey, haveinvented certain new and useful Improvements in. Press Guards, of whichthe following is a specificat on.

This invention relates to safety devices as applied to treadleControlled machinery and particularly to such types as power actuatedpunch presses.

One of the objects of the invention is to provide a barrier or guardwith means whereby it is interposed between the operator and danger zoneofthe press, imme diately prior to the descent of the ram or plunger tomake contact with the work part disposed on the die or fixedportion ofthe press.

A further purpose is to produce means which prevent operation of thepress until the guard has completed contact with the platen of thepress, irrespective of treadle movement, thus avoiding premature actionof the press likely to damage any intervening obiect between the guardand platen.

Another aim is in the provision of means to prevent the untimely descentof the guard and hence action of the press.

' These several aims, objects and purposes,

application, adjustability and efficiency, are attained by the novelconstruction, combination and arrangement of parts hereafter describedand shown in the accompanying drawings, forming a material part of thisdisclosure, and in which Figure 1, is a front elevational view of aconventional type of power punch press,

showingthe application of an embodiment of the invention.

Figure 2 is a side View of the same. ,lligure 3 isa perspective viewshowing the main operative parts of the invention in detail.

Figure 4 is an enlarged transverse sectional view take-non line of Fig.3.

Figure 5 is a fragmentary side view of the guard latch operating means.

Figure 6 is an enlarged sectional View taken .on line 6-6 of Figure 1.

An inclined type of punch press is illustrated in the, drawing, the samebeing composed ofa body 15, itsourved base being adjustably, mounted onlegs 16 and having of the fork another bearings 17 in its upper portionfor the shaft 18.

Thlsshaft extends outward at one end to accommodate a clutch, generallydesignated by the numeral 19, and beyond the.

reciprocative motion to the ram or plunger 22, slidable in guides 23 atthe frontof the press, to which a punch 24 may beattached and on the bed25 is a bolster 26 to which is clamped the die block 27 carrying a die28.

The press is put in operation by depressing a treadle or foot lever 29,normally held in a raised positionby the tension spring 30, movement ofthe treadle being communicatcd to the clutch 19 by a rod .31. which maybe adjusted in operativelength by a turnbuckle 32.

The foregoing is generally descriptiveof any common type of singleacting, power operated press and given only to illustrate theapplication of the invention, the dis closure of which follows.

In place of the rod 31 directly connecting with the, clutch device, anarm 33 is pivoted at the rear of the press, at 34, to extend towards thefront at either side of the press and to this arm the upper end of therod 31 is connected and an additional rod 351s used to connect the arm wth the Clutch.

Fixed on the forward end of the arm 33 containing slots 37 and at apoint rearward pa1r of plates 38 are fixed on the arm. these platescarrying a pivot 39 on which a forwardly extending lever 40 is mounted.

The lever is guided between the plates 36 and has fixed in it a pin 41operable in the slots 37 limiting the relative motion of the lever andarm and in addition to the weight of thelever, a spring 42 is interposedbetween the arm and lever tending to press the latter element forciblydownward.

The outer end of the lever is bent to extend, as at40', in front of thepress and has engaged with it an adjustable bar 43 held by clamp screws,this bar extending substantially horizontal in front of the plunger 22.

Attached near the end of the ,bar 43 is a flat upright stem 44, slottedfor vertical adjustment and provided with means for clamping to the bar,this stem being integral with a guard plate 45 extending across thefront of the plunger at its lower end and movable by action of thetreadle to make contact with the bolster or press bed as shown by thebroken lines in Figure 2.

It is to be noted that a full and complete movement of the guard musttake place before the clutch rod 35 can be moved to engage the clutch,due to the pin 4L1 making Contact with the upper end of the slot 37,thus preventing it from transmitting suiiicient movement of the arm 33,in case of some object being interposed between the lower edge of theguard plate 4-5 and the bolster 26, when the parts are properlyadjusted.

The guard plate 45 is shown as apertured to permit a view of the workwhen in its lowered. position and is suiiiciently rigid to effectivelyprevent dislocation by the hands of an operator.

It is also apparent that if the hands he so placed as to be struck bythe guard descending by pressure applied to the treadle, the

blow will be cushioned by the spring 42, permitting withdrawal withoutserious damage being done and that the plunger cannot descend untilafter such removal of the hands or other objects which may beinadvertently interposed.

In order to maintain the guard in a lowered position and thus assure areciprocative movement of the plunger, even if the treadle should bereleased prematurely or before the clutch elements have made operativeengagement, the device shown in Figs. 1, 5 and 6 is used.

This device consists of a horizontal bracket 4-6 rigidly fixed to one ofthe press plunger guides 23, on the side adjacent the arm and lever,near its lower end, the bracket having a longitudinal slot 47 suited toreceive and guide a slide L8 provided with a bevelled outwardlyextending end 49 and containing a recess 50, the rear wall 51 of whichis also correspondingly bevelled.

Access is had to the recess 50 through an opening 52 in the outer wallof the bracket 46. this wall also containing a slot 53 through whichextends a pin 54, fixed in the slide 48, to which one end of a tensionspring 59 is attached, its outer end being engaged with a pin 60 linedin the bracket and adapted to draw the slide outwardly.

The latch-like bevelled end 49 of the slide is thus normally held in thepath of the arm 33, said arm at its free end being provided with anoutwardly extending projection 33' designed to engage with thelatch-like bevelled end 49 of the slide when the arm 33 movesdownwardly, thereby pressing the slide back into the bracket, until thearm has fully passed, whereupon the spring 59 draws the slide out, thuspreventing the return of the arm.

The slide however is retracted by the bevelled end (31 of an arm 62,rigidly held on the side of the plunger 22, this arm entering the recess50 and making contact with the element 51, moving the slide 48 back andholding it there. clearing the path of the projection 33 of the arm 33until the plunger has made its stroke and is beginning to rise to itsnormal position.

Thus it will be seen that the guard 45 cannot rise prematurely but willremain in downward operative position until the plunger has fullycompleted its downward stroke and is beginning to rise to its normalupper position, assuring safety to the operator irrespective of treadleaction made inter veningly.

From the foregoing it will be seen that a simple device for this purposehas been disclosed in the preferred form of its embodiment. but it isnot desired to restrict the details to the exact construction shown. itbeing obvious that changes, not involving the exercise of invention, maybe made without conflicting with the scope of the appended claims.

Having thus described my invention. what I claim as new and desire tosecure by Letters Patent, is

1. In a device of the class described, the combination with a punchpress having a frame, a bed, a power driven clutch actuated crank shaft,a plunger operated thereby and a pedal controlling said clutch, of anarm pivoted on said frame, a rod directly connected between said arm andpedal, said arm being operatively engaged with said clutch, a leverpivoted on the arm, means for limiting the relative movement of said armand lever, saidlever having its front end bent to extend in front ofsaid plunger, and a depending guard adjustably secured to said lever.

2. In a device of the class described, the combination with a powerpunch press, of a guard disposed in front of the plunger, a bar to whichthe stem element of said guard is adiustably attached, a lever bent toadjustably support said bar, an arm pivoted to the frame of the press,said lever being pivoted on said arm, pedal means for actuat ing saidarm, means for preventing the press from operating prior to the fulldescent of said guard, a latch on the side of said press, said latchpreventing the rise of said arm, and means carried by the plunger ofsaid press for releasing said latch.

3. In a device of the class described, the combination with a punchpress having a frame, a bed, a power driven clutch actuated crank shaft,a plunger operated thereby and a pedal controlling said clutch, of anarm pivoted on said frame, a rod directly connected between said arm andpedal, said arm being operatively engaged with said clutch, a leverpivoted on the arm, means for limiting the relative movement of said armand lever, said. lever having its front end bent to extend in front ofsaid plunger, and a guard adjustably carried on said lever, said guardbeing adapted to make contact with the bed of the press prior topermitting full movement of said arm.

4. In a device of the class described, the combination with a punchpress having a frame, a bed, a power driven clutch actuated c 'ankshaft, a plunger operated thereby and a pedal controlling said clutch,of an arm pivoted on said frame, a rod directly connected between saidarm and pedal, said arm being operatively engaged with said clutch, alever pivoted on the arm, a forked guide at the outer end of the arm inwhich the lever operates, said guide being slotted, a spring in theguide tending to press said lever downward, said'lever being bent toextend in front of said plunger, a depending guard plate adjustablyattached to the bent end of said lever, and a pin in said leveroperative in the slot of said guide, preventing completion of movementof said arm until said plate has reached the lowest point permissible bysaid bed.

5. In a device of the class described, the combination with a punchpress having a frame, a bed, a power driven clutch actuated crank shaft,a plunger operated thereby and a pedal controlling said clutch, of anarm pivoted on said frame, a rod directly connected between said arm andpedal, said arm being operatively engaged with said clutch, aleverpivoted on the arm, means for limiting the relative movement of said armand lever, said lever having its front end bent to extend in front ofsaid plunger, a guard adjustably carried on said lever, said guard beingadapted to swing into contact with the bed of the press prior to thecompletion of full movement of said arm, a spring actuated sliding latchon the frame of the press normally intercepting the upward movement ofsaid arm, and means carried by said plunger for removing said latch fromthe path of said arm when said plunger is beginning to rise to its upperposition.

This specification signed and witnessed this 24th day of August, 1923.

FRANZ A. FULLER. lVitnesses A. B. UNDERHILL, PAUL E. HARTMAN.

